How To Rewrite URLs with mod_rewrite for Apache on Ubuntu 20.04

Introduction

In this tutorial, we will activate and learn how to manage URL rewrites using Apache 2’s mod_rewrite module. This module allows us to rewrite URLs in a cleaner fashion, translating human-readable paths into code-friendly query strings or redirecting URLs based on additional conditions.

This guide is split into two parts. The first sets up an example website and covers a simple rewrite example. The second part contains two more in-depth examples of commonly-used rewrite rules.

Prerequisites

To follow this tutorial, you will need:

• One Ubuntu 16.04 server set up with this initial server setup tutorial, including a sudo non-root user and firewall.
• Apache 2 installed on your server by following Step 1 of How To Install Linux, Apache, MySQL, PHP (LAMP) stack on Ubuntu 16.04.

Step 1 — Enabling mod_rewrite

First, we need to activate mod_rewrite. It’s available but not enabled with a clean Apache 2 installation.

sudo a2enmod rewrite

This will activate the module or alert you that the module is already enabled. To put these changes into effect, restart Apache.

sudo systemctl restart apache2

mod_rewrite is now fully enabled. In the next step we will set up an .htaccess file that we’ll use to define rewrite rules for redirects.

Step 2 — Setting Up .htaccess

An .htaccess file allows us to modify our rewrite rules without accessing server configuration files. For this reason, .htaccess is critical to your web application’s security. The period that precedes the filename ensures that the file is hidden.

Note: Any rules that you can put in an .htaccess file can be also put directly into server configuration files. In fact, the official Apache documentation recommends using server configuration files instead of .htaccess because Apache processes it faster that way.

However, in this simple example, the performance increase will be negligible. Additionally, setting rules in .htaccess is convenient, especially with multiple websites on the same server. It does not require a server restart for changes to take effect and it does not require root privileges to edit those rules, simplifying maintenance and and making changes possible with unprivileged account. Some popular open-source software, like WordPress and Joomla, often relies on an .htaccess file for the software to modify and create additional rules on demand.

We will need to set up and secure a few more settings before we can begin.

By default, Apache prohibits using an .htaccess file to apply rewrite rules, so first you need to allow changes to the file. Open the default Apache configuration file using nano or your favorite text editor.

sudo nano /etc/apache2/sites-available/000-default.conf

Inside that file, you will find a <VirtualHost *:80> block starting on the first line. Inside of that block, add the following new block so your configuration file looks like the following. Make sure that all blocks are properly indented./etc/apache2/sites-available/000-default.conf

<VirtualHost *:80>
    <Directory /var/www/html>
        Options Indexes FollowSymLinks MultiViews
        AllowOverride All
        Require all granted
    </Directory>

    . . .
</VirtualHost>

Save and close the file. To put these changes into effect, restart Apache.

sudo systemctl restart apache2

Now, create the .htaccess file in the web root.

sudo nano /var/www/html/.htaccess

Add this line at the top of the new file to activate the rewrite engine./var/www/html/.htaccess

RewriteEngine on

Save the file and exit.

You now have an operational .htaccess file which you can use to govern your web application’s routing rules. In the next step, we will create sample website files that we’ll use to demonstrate rewrite rules.

Step 3 — Configuring URL Rewrites

Here, we will set up a basic URL rewrite, which converts pretty URLs into actual paths to code. Specifically, we will allow users to access http://your_server